Postal scales are well known in the art as are portable weighing scales which can be moved from place to place or left on a counter or other surface at a particular location and which have remotely positioned displays separate from the weighing platform, such as disclosed in U.S. Pat. Nos. 2,805,055; 3,106,975; 3,469,645; 4,273,205; 4,537,266; 4,632,199; and 4,979,579. In this regard, U.S. Pat. No. 3,106,975 discloses such a portable scale which opens in size to accommodate large size packages such as suitcases and luggage, in which the weight display is pneumatically coupled to the scale on the side so as to assist in visibility of the display from above when a large size package is positioned on the scale; however, the display location is fixed and thus, limits visibility if the package has a dimension larger in size than the fixed position of the side located display. Moreover, since the display location is fixed in a fully extended position, the scale cannot be made more compact for smaller packages which can create problems when space is at a premium, such as in an office mailroom environment. Similarly, U.S. Pat. No. 4,537,266 discloses a portable scale in which the longitudinal extent of the horizontal display is also fixed resulting in the same problems as discussed above.
U.S. Pat. No. 4,979,579 discloses a portable weighing device, namely an electronic balance, in which the horizontal display pivots about the weighing area and telescopes merely to adapt to the contour of the weighing area. However, the display is not longitudinally extendable so as to be able to be viewed from above irrespective of the size of the package placed on the scale. This is not surprising since the disclosed balance contains a fixed size chamber which is intended to accommodate the material to be weighed inside this chamber rather than to weigh removable packages of variable size or dimension, such as what is normally done in using a postal type scale.
With respect to U.S. Pat. Nos. 2,805,055; 3,469,645; 4,273,205; and 4,632,199, although all of the disclosed weighing devices have separate remote displays, these displays are not also longitudinally extendable from the scale so as to be visible from above while also retracting to a compact position within the scale base so as to minimize the space for the scale and the display both of which are particularly desirable in office mail room environments, for example, where the amount of the space allocated for a postal type scale is often severely limited.
Thus, none of the prior art portable scales known to applicant is capable of providing a compact postal type scale capable of weighing a plurality of different size or dimension packages in which a horizontal weight display is longitudinally extendable from the scale base along the supporting surface so as to be visible from above no matter what the size of the package placed on the scale throughout a given size range, while also being retractable to a compact rest position in the scale base for normal size packages. These disadvantages of the prior art are overcome by the present invention.